Speedometer failure question
 

So I had my car sitting for about a year in the garage. When I parked it, the speed and tach both worked perfectly every time (and the odometer too).

After starting it up the other day - the speedo, tach, and odometer were all dead. Other cluster gauges such as fuel, water temp worked fine and so did the backlighting.

I let the car sit one week and now the odometer is turning on (with like every bar lit up - not readable digits) but the speedo/tach are still not working. I hooked up my FC Commander and the RPM monitoring function was working fine, but when I tried to monitor SPEED, it just shows nothing.

I read the threads about the capacitors so I will pull the cluster probably and check those.

My question is - Does the fact that the FC Commander could read the rpm OK but not the speed tell us anything about the speedometer signal wiring? I'm not sure if the Commander is getting the signal straight off the speedo drive gear/sensor or if it gets it some other way.

Thanks,
B

Try disconnecting the battery and reconnect the terminals in the other order. In one of thd old threads it was noted that when done in the wrong sequence the odo wont be happy.

Interesting, do you have a link? I've never read that!

Similar problems in the past. If I unhooked the battery and charged it Fully, reconnected and everything came back alive.

no, the speedo sensor goes right to the speedo, and then there is an output for the ECU

Thought I would add some pictures. The first three show the big capacitor. What stands out as possible issues to me are the following:

1 - One leg has burned/black stuff around the bottom. This is probably burned up leaked electrolyte.

2 - One leg has a greenish fuzzy appearance - more leaking.

3 - The bottom of the capacitor is bulging down toward the circuit board. It is sort of hard to see, but look for a black bulge in the third pic.

https://www.rx7club.com/attachment.p...1&d=1408561261
https://www.rx7club.com/attachment.p...1&d=1408561261
https://www.rx7club.com/attachment.p...1&d=1408561261

This transistor (TR5) looks somewhat suspicious to me too. While there does not appear to be any physical damage to it, the board looks sort of overheated where it is soldered on. Not sure if this means it's bad or not. I ordered a new part for that too but I'm not sure if I'll replace it or not at this point.

https://www.rx7club.com/attachment.p...1&d=1408561261
https://www.rx7club.com/attachment.p...1&d=1408561261

Are you going to try to solder the new capacitors on yourself? Please keep us posted on the result.